package com.yyl.common.util.dynamic;

import com.yyl.common.constant.Inter.DataBaseConstant;
import com.yyl.common.system.vo.DynamicDataSourceModel;
import org.apache.commons.lang.StringUtils;

import java.text.MessageFormat;
import java.util.Map;

/**
 * 根据不同的数据库，动态生成SQL，例如分页
 */
public class SqlUtils {
	public static final String DATABSE_TYPE_MYSQL = "mysql";
	public static final String DATABSE_TYPE_POSTGRE = "postgresql";
	public static final String DATABSE_TYPE_ORACLE = "oracle";
	public static final String DATABSE_TYPE_SQLSERVER = "sqlserver";
	
	/**
	 * 分页SQL
	 */
	public static final String MYSQL_SQL = "select * from ( {0}) sel_tab00 limit {1},{2}";
	public static final String POSTGRE_SQL = "select * from ( {0}) sel_tab00 limit {2} offset {1}";
	public static final String ORACLE_SQL = "select * from (select row_.*,rownum rownum_ from ({0}) row_ where rownum <= {1}) where rownum_>{2}";
	public static final String SQLSERVER_SQL = "select * from ( select row_number() over(order by tempColumn) tempRowNumber, * from (select top {1} tempColumn = 0, {0}) t ) tt where tempRowNumber > {2}";
	
	/**
	 * 获取所有表的SQL
	 */
	public static final String MYSQL_ALLTABLES_SQL = "select distinct table_name from information_schema.columns where table_schema = {0}";
	public static final String POSTGRE__ALLTABLES_SQL = "SELECT distinct c.relname AS  table_name FROM pg_class c";
	public static final String ORACLE__ALLTABLES_SQL = "select distinct colstable.table_name as  table_name from user_tab_cols colstable";
	public static final String SQLSERVER__ALLTABLES_SQL = "select distinct c.name as  table_name from sys.objects c";
	
	/**
	 * 获取指定表的所有列名
	 */
	public static final String MYSQL_ALLCOLUMNS_SQL = "select column_name from information_schema.columns where table_name = {0} and table_schema = {1}";
	public static final String POSTGRE_ALLCOLUMNS_SQL = "select table_name from information_schema.columns where table_name = {0}";
	public static final String ORACLE_ALLCOLUMNS_SQL = "select column_name from all_tab_columns where table_name ={0}";
	public static final String SQLSERVER_ALLCOLUMNS_SQL = "select name from syscolumns where id={0}";
	
	/*
	 * 判断数据库类型
	 */
	public static boolean dbTypeIsMySQL(String dbType) {
		return dbTypeIf(dbType, DATABSE_TYPE_MYSQL, DataBaseConstant.DB_TYPE_MYSQL_NUM);
	}
	
	public static boolean dbTypeIsOracle(String dbType) {
		return dbTypeIf(dbType, DATABSE_TYPE_ORACLE, DataBaseConstant.DB_TYPE_ORACLE_NUM);
	}
	
	public static boolean dbTypeIsSQLServer(String dbType) {
		return dbTypeIf(dbType, DATABSE_TYPE_SQLSERVER, DataBaseConstant.DB_TYPE_SQLSERVER_NUM);
	}
	
	public static boolean dbTypeIsPostgre(String dbType) {
		return dbTypeIf(dbType, DATABSE_TYPE_POSTGRE, DataBaseConstant.DB_TYPE_POSTGRESQL_NUM);
	}
	
	/**
	 * 判断数据库类型
	 */
	public static boolean dbTypeIf(String dbType, String... correctTypes) {
		for (String type : correctTypes) {
			if (type.equalsIgnoreCase(dbType)) {
				return true;
			}
		}
		return false;
	}
	
	/**
	 * 获取全 SQL
	 * 拼接 where 条件
	 *
	 * @param sql
	 * @param params
	 * @return
	 */
	public static String getFullSql(String sql, Map params) {
		return getFullSql(sql, params, null, null);
	}
	
	/**
	 * 获取全 SQL
	 * 拼接 where 条件
	 * 拼接 order 排序
	 *
	 * @param sql
	 * @param params
	 * @param orderColumn 排序字段
	 * @param orderBy     排序方式，只能是 DESC 或 ASC
	 * @return
	 */
	public static String getFullSql(String sql, Map params, String orderColumn, String orderBy) {
		StringBuilder sqlBuilder = new StringBuilder();
		sqlBuilder.append("SELECT t.* FROM ( ").append(sql).append(" ) t ");
		if (params != null && params.size() >= 1) {
			sqlBuilder.append("WHERE 1=1 ");
			for (Object key : params.keySet()) {
				String value = String.valueOf(params.get(key));
				if (StringUtils.isNotBlank(value)) {
					sqlBuilder.append(" AND (").append(key).append(" = N'").append(value).append("')");
				}
			}
			if (StringUtils.isNotBlank(orderColumn) && StringUtils.isNotBlank(orderBy)) {
				sqlBuilder.append("ORDER BY ").append(orderColumn).append(" ").append("DESC".equalsIgnoreCase(orderBy) ? "DESC" : "ASC");
			}
		}
		return sqlBuilder.toString();
	}
	
	/**
	 * 获取求数量 SQL
	 *
	 * @param sql
	 * @return
	 */
	public static String getCountSql(String sql) {
		return String.format("SELECT COUNT(1) \"total\" FROM ( %s ) temp_count", sql);
	}
	
	/**
	 * 生成分页查询 SQL
	 *
	 * @param dbType 数据库类型
	 * @param sql
	 * @param page
	 * @param rows
	 * @return
	 */
	public static String createPageSqlByDBType(String dbType, String sql, int page, int rows) {
		int beginNum = (page - 1) * rows;
		Object[] sqlParam = new Object[3];
		sqlParam[0] = sql;
		sqlParam[1] = String.valueOf(beginNum);
		sqlParam[2] = String.valueOf(rows);
		if (dbTypeIsMySQL(dbType)) {
			sql = MessageFormat.format(MYSQL_SQL, sqlParam);
		} else if (dbTypeIsPostgre(dbType)) {
			sql = MessageFormat.format(POSTGRE_SQL, sqlParam);
		} else {
			int beginIndex = (page - 1) * rows;
			int endIndex = beginIndex + rows;
			sqlParam[2] = Integer.toString(beginIndex);
			sqlParam[1] = Integer.toString(endIndex);
			if (dbTypeIsOracle(dbType)) {
				sql = MessageFormat.format(ORACLE_SQL, sqlParam);
			} else if (dbTypeIsSQLServer(dbType)) {
				sqlParam[0] = sql.substring(getAfterSelectInsertPoint(sql));
				sql = MessageFormat.format(SQLSERVER_SQL, sqlParam);
			}
		}
		return sql;
	}
	
	/**
	 * 生成分页查询 SQL
	 *
	 * @param sql
	 * @param page
	 * @param rows
	 * @return
	 */
	public static String createPageSqlByDBKey(String dbKey, String sql, int page, int rows) {
		DynamicDataSourceModel dynamicSourceEntity = DataSourceCachePool.getCacheDynamicDataSourceModel(dbKey);
		String dbType = dynamicSourceEntity.getDbType();
		return createPageSqlByDBType(dbType, sql, page, rows);
	}
	
	private static int getAfterSelectInsertPoint(String sql) {
		int selectIndex = sql.toLowerCase().indexOf("select");
		int selectDistinctIndex = sql.toLowerCase().indexOf("select distinct");
		return selectIndex + (selectDistinctIndex == selectIndex ? 15 : 6);
	}
	
	public static String getAllTableSql(String dbType, Object... params) {
		if (StringUtils.isNotEmpty(dbType)) {
			if (dbTypeIsMySQL(dbType)) {
				return MessageFormat.format(MYSQL_ALLTABLES_SQL, params);
			} else if (dbTypeIsOracle(dbType)) {
				return ORACLE__ALLTABLES_SQL;
			} else if (dbTypeIsPostgre(dbType)) {
				return POSTGRE__ALLTABLES_SQL;
			} else if (dbTypeIsSQLServer(dbType)) {
				return SQLSERVER__ALLTABLES_SQL;
			}
		}
		return null;
	}
	
	public static String getAllColumnSQL(String dbType, Object... params) {
		if (StringUtils.isNotEmpty(dbType)) {
			if (dbTypeIsMySQL(dbType)) {
				return MessageFormat.format(MYSQL_ALLCOLUMNS_SQL, params);
			} else if (dbTypeIsOracle(dbType)) {
				return MessageFormat.format(ORACLE_ALLCOLUMNS_SQL, params);
			} else if (dbTypeIsPostgre(dbType)) {
				return MessageFormat.format(POSTGRE_ALLCOLUMNS_SQL, params);
			} else if (dbTypeIsSQLServer(dbType)) {
				return MessageFormat.format(SQLSERVER_ALLCOLUMNS_SQL, params);
			}
		}
		return null;
	}
}
